[S390] tape: remove unused/not handled return codes

Return codes are on purpose not handled or used. So remove them.

Acked-by: Michael Holzheu <[e-mail]>
Signed-off-by: Heiko Carstens <[e-mail]>
Signed-off-by: Martin Schwidefsky <[e-mail]>

drivers/s390/char/tape_3590.c

···
 static int tape_3590_crypt_error(struct tape_device *device,
 				 struct tape_request *request, struct irb *irb)
 {
-	u8 cu_rc, ekm_rc1;
+	u8 cu_rc;
 	u16 ekm_rc2;
-	u32 drv_rc;
 	char *sense;
 
 	sense = ((struct tape_3590_sense *) irb->ecw)->fmt.data;
 	cu_rc = sense[0];
-	drv_rc = *((u32*) &sense[5]) & 0xffffff;
-	ekm_rc1 = sense[9];
 	ekm_rc2 = *((u16*) &sense[10]);
 	if ((cu_rc == 0) && (ekm_rc2 == 0xee31))
 		/* key not defined on EKM */

drivers/s390/char/tape_std.c

···
 tape_std_mtreten(struct tape_device *device, int mt_count)
 {
 	struct tape_request *request;
-	int rc;
 
 	request = tape_alloc_request(4, 0);
 	if (IS_ERR(request))
···
 	tape_ccw_cc(request->cpaddr + 2, NOP, 0, NULL);
 	tape_ccw_end(request->cpaddr + 3, CCW_CMD_TIC, 0, request->cpaddr);
 	/* execute it, MTRETEN rc gets ignored */
-	rc = tape_do_io_interruptible(device, request);
+	tape_do_io_interruptible(device, request);
 	tape_free_request(request);
 	return tape_mtop(device, MTREW, 1);
 }